Temperature measuring devices are used to measure a temperature of a target object. The temperature measuring devices are based on various principles. Examples of the devices include a device utilizing thermal expansion of a substance, and a device using a thermocouple that converts a temperature difference into a voltage.
These temperature measuring devices generally measure a temperature of a target object in a state in contact with the target object.
Meanwhile, there also are devices, such as thermographic cameras, that measure a temperature of a target object in a state not in contact with the target object. A thermographic camera is described, for example, in Patent Literature (PTL) 1 specified below. The thermographic camera includes a two-dimensional array of infrared detecting elements arranged in two dimensions. The thermographic camera receives infrared rays from a target object, at the two-dimensional array, and on the basis of the received infrared rays, visualizes the temperature distribution of the target object, for example, by displaying the distribution on a display.
The following PTL 2 and Non-Patent Literatures (NPL) 1 and 2 are related to configuration examples of the present invention described later.